Organic Chemistry, explained by patterns
This site teaches organic chemistry as a small set of reusable ideas: electron flow, stability, and structure → reactivity. Use the left navigation to follow a learning path, and the Practice section for interactive drills.
The big ideas (what to memorize vs understand)
Most exam problems reduce to: (1) identify the most nucleophilic/basic site, (2) identify the best electrophile/leaving group, (3) predict the dominant pathway (substitution, elimination, addition, rearrangement), and (4) check stereochemistry.
| Idea | What it controls | Fast check |
|---|---|---|
| Stability (resonance, induction, hyperconjugation) | Acidity, carbocation/radical stability, regioselectivity | Can I delocalize charge? Is an electronegative atom nearby? |
| Orbital overlap | SN2 rate, stereospecificity, pericyclic outcomes | Is backside attack possible? Is the electrophile hindered? |
| Thermodynamic vs kinetic | Product distributions | Low T/short time → kinetic; high T/equilibration → thermodynamic |
How to succeed in Organic Chemistry
Organic chemistry is not about memorizing 100 reactions; it's about learning 5 patterns and applying them to 100 scenarios.
Always look for the most electronegative atom. It holds the negative charge (nucleophile) or creates a partial positive charge next to it (electrophile).
Don't do mechanism problems in your head. Draw the lone pairs, draw the H atoms on stereocenters, and draw the arrows.
If a molecule has resonance, it is stable. If an intermediate has resonance, it will form faster. Check for allylic lone pairs and pi bonds.
If a reagent is bulky (like t-BuOK), it acts as a base, not a nucleophile. If a carbon is crowded (tertiary), SN2 can't happen.
What to practice daily
Short, frequent drills build speed and accuracy:
- Rank acidity/basicity using resonance + induction + hybridization.
- Decide SN1/SN2/E1/E2 from substrate + solvent + nucleophile/base.
- Assign R/S and E/Z; recognize meso compounds.
- Translate spectra → structure (IR functional group, 1H NMR splitting + integration).